Computed tomography (CT) is an imaging procedure that uses specialized X-ray equipment to create detailed pictures, or scans, of areas inside a scanned object (e.g., a living body). Multiple X-ray images taken from different angles may be utilized to produce cross-sectional tomographic images (virtual “slices”) of specific areas of the scanned object. Medical imaging is one of the most common applications of CT. The cross-sectional images are used for diagnostic and therapeutic purposes in various medical disciplines.
Positron emission tomography (PET) is a radioisotope emission (RE)-based imaging technique that detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer), which is introduced into the body on a biologically active molecule. Three-dimensional images of tracer concentration within the body are then constructed by computerized analysis.
Positron emission tomography-computed tomography (PET-CT) is an imaging technique which combines, in a single gantry, a PET scanner and an X-ray CT scanner, to acquire sequential images from both devices in the same session, which are combined into a single superposed image.